The 'celestial pearl danio', a new genus and species of colourful minute cyprinid fish from Myanmar (Pisces: Cypriniformes)

Abstract

Celestichthys margaritatus, a new genus and species of Danioinae, is described from a rapidly developing locality in the Salween basin about 70-80 kin northeast of Inle Lake in northern Myanmar. Males and females are strikingly colouful. It is apparently most closely related to two danioins endemic to Inle, Microrasbora rubescens and "Microrasbora" erythromicron. The latter species may be congeneric with the new species. The new genus is identified as a danioin by specializations on its lower jaw and its numerous anal fin rays. The colouration, while highly distinctive, seems also to be characteristically danioin. The danioin notch (Roberts, 1986; Fang, 2003) is reduced or absent, but the danioin mandibular flap and bony knob (defined herein) are present. The anal fin has iii81/2-101/2 rays. In addition to its distinctive body spots and barred fins the new fish is distinguished from other species of danioins by the following combination of characters: snout and mouth extremely short; premaxillary with an elongate and very slender ascending process; mandible foreshortened; body deep, with rounded dorsal and anal fins; modal vertebral count 15+16=31; caudal fin moderately rather than deeply forked; principal caudal fin rays 9/8; scales vertically ovoid; and pharyngeal teeth conical, in three rows